Jerome W. Bettman, M.D., and
Gilbert
W. Cleasby,
M.D.Presbyterian Medical Center, San Francisco, California
(Submitted July 10, 1962; accepted December 17.)
This study was aided by a grant from the Broemmel Pharmaceutical Company.
ADDRESS: (J.W.B.) 2400 Clay Street, San Francisco 15, California.
PEDIAi-iucs, September 1963
420
E ARLY RECOGNITION of congenital
glau-coma in an infant may make the differ-ence between a life of blindness and a life
with sight. The incidence of primary
con-genital glaucoma in all births is estimated
to be approximately 0.05%. Glaucoma, how-ever, accounts for 5 to 13% of the inmates of schools for the blind. Approximately two-thirds of cases occur in males.
Three-quar-ters are bilateral, although the second eye
may be affected later than the first. In
75%
of cases, congenital glaucoma is diagnosed
before the end of the first year of life, with the majority found within the first few months; 17% of cases are diagnosed between
the first to third year of life; and
approxi-mately 9% are diagnosed after the third
year.
CLINICAL FEATURES
The manifestations of glaucoma in infants
are different from those associated with
open angle (chronic) glaucoma in adults. These differences provide the key to early diagnosis. Photophobia, blepharospasm, and epiphora frequently result from elevated intraocular pressure in the infant eye. The
importance of photophobia cannot be
over-emphasized. It is the first sign of congenital glaucoma in approximately one-half of all
cases.1 Photophobia before the age of one
year means glaucoma, until proved other-wise. Photophobia also provides some in-dication of control, since it tends to persist until the pressure has been normalized. The
eyes sometimes appear slightly red. It is
unfortunate that many cases of congenital glaucoma have been misdiagnosed as
bleph-antis or conjunctivitis and treated with yellow oxide of mercury or topical anti-biotics.
Congenital glaucoma may be present in an advanced state at birth. The conneas may be very large or porcelain white. On
the other hand, the course may be insidious, with gradual enlargement of the corneas
and slight irritability of the eyes. It is well to bear in mind also that the course may be cyclical and acute exacerbations occur. Between exacerbations the intraocular pres-sure may be perfectly normal. The examiner
must be on guard and realize that a normal measurement on one occasion does not
mean that congenital glaucoma is not present.
The infant eyeball is distensible under pressure, unlike the eye of an adult. This effect is noted especially in the cornea,
which becomes progressively larger under continued elevated pressure.
Thus, the infant with congenital glaucoma
typically
presents with these findings : hiscorneas are large, he is sensitive to light, and the globes may appear slightly irritated
on reddish (Fig. 1).
These signs and symptoms may vary, of course, and not all may be present. The
corneas may be completely clear, may
appear hazy, or may even be porcelain
white in the most advanced cases. Corneal
opacification is due to edema which is first
epithelial, then later involves the stroma.
Tears developing in Descemet’s membrane are more frequent inferiorly and tend to follow a horizontal direction. The parents may simply state that there is “no life” in the eyes.
The corneal diameter may be looked upon as having the same relationship to
congenital glaucoma as the visual field has
and control. Just as a very small visual field
in adult glaucoma indicates an advanced
case with a guarded prognosis, so does a
very large cornea in congenital glaucoma. If the cornea is less than 13 mm in diam-(‘ten, the prognosis is good; if it is 13-14
mm in diameter, the prognosis is fair; if it
is over 14 mm, the prognosis is poor. If the
corneal diameter increases over a period of time, it is an indication that the intraocular pressure has not been constantly normal,
just as the visual field in adult glaucoma indicates lack of control if it becomes
pro-gressively smaller.
The following figures are helpful in
judging the average horizontal diameter of
the cornea in infancy (figures in
paren-theses show the statistical average) : at birth, 9.5 mm (9.44 mm); at 6 months, 10.5
mm (10.82 mm); and at 1 year, 11.5 mm (11.39 mm).
Beyond the first year of life the corneal
diameter normally increases very little. If the cornea is more than 11 mm in the
new-born or more than 12 mm in diameter at
any age, one should be highly suspicious.
The corneal diameter should be measured with calipers under magnification.
Meas-urements with reasonable accuracy to 0.25
mm can be obtained.
Cupping and atrophy of the nerve head
FIG. 1. This 5-month-old boy with congenital glaucoma shows enlarged corneas (right, 13 mm;
left, 14 mm) and tearing.
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FIG. 2. (From Troncoso, MU. : Gonioscopy, Phil-adelphia, F. A. Davis Co., 1948, p. 114. Reprinted with permission.) Angle of the anterior chamber of a normal eye as seen through a Koeppe con-tact lens (R) an(l in cross-section (L). The goni-otomv incision is made in the trabeculum (Tr)
between Schlemm’s canal (CS) and Schwahhe’s line (D, Schw).
can be seen, but are usually late findings,
since the cornea in an infant gives way
under pressure more readily than the lamina cnibrosa of the optic disc.
The preferred therapy provides another striking difference between congenital and open angle adult glaucoma, in that the
former is surgical and the latter is medical. It has been well established that congenital glaucoma cannot be successfully treated by
medical means. The use of such therapy as miotics and carbonic anhydrase inhibitors
(
e.g., Diamox) are only ancillary measures.The treatment of choice is the goniotomy operation.
DIAGNOSIS
The final diagnosis of congenital glau-coma can usually be made only when the infant is tinder general anesthesia. Examina-tion should be performed by or with the
help of an ophthalmologist who is especially vell acquainted with this disease. The
par-ents should be informed that surgery will be performed under the same anesthesia if the diagnosis is confirmed. One should be
study the angle of the anterior chambers,
and (4) examine the fundi. We shall
corn-ment on each of these procedures.
If intraocular pressure measures more than 3 units with a 5.5-gm weight on the Schi#{246}tz tonometer (less than 25 mm Hg) it is regarded as normal. However, increased pressure may be cyclical, and one normal
measurement does not prove the absence of the condition. If the pressure measures 2
units or less with a 5.5 gm weight (more
than 29 mm Hg) one should operate.2 The intraocular pressure may register higher than it actually is if the anesthesia is not
sufficiently deep. Intubation is desirable, and topical anesthetic drops should be used in addition to the general anesthesia.
The anesthesia should be sufficiently deep that the eyes are straight spontaneously and
do not turn up or inward. The intraocular pressure may register lower than it actually
is if the infant has become dehydrated. Other less important factors influencing
these measurements are abnormal corneal
curvature and decreased scieral rigidity. The horizontal diameter of the cornea should be measured with calipers under magnification. If the corneal epithelium is hazy, it can be removed to obtain a better
evaluation of stromal opacification, defects in Descemet’s membrane, angle details, and
fundus findings.
Examination of the angle of the anterior
chamber is done through a large contact lens. Although one cannot diagnose the presence or absence of congenital glaucoma
by the appearance of the angle, there is
often a typical appearance; the distribution
of vessels can be seen and one can evaluate
the area to be operated (especially if there has been previous surgery).
Examination of the fundus can be per-formed through a smooth-surfaced Koeppe
contact lens in order to eliminate
irregular-ity of the cornea.2 Ophthalmoscopic study
usually reveals normal details, but one
should be aware of any associated congeni-tal abnormalities. In advanced cases there may be cupping of the disc.
DIFFERENTIAL DIAGNOSIS
Blephariti and Con/unctivitis: As
mdi-cated above, photophobia, lacrimation,
in-nitability and redness of the eye are not infrequently due to blepharitis and/or
con-junctivitis.
Megalocornea: In this condition the
cor-neas are congenitally large, although there
is no increase in intraocular pressure, and the vision is good. It is not as difficult to
differentiate from congenital glaucoma as it might seem. The corneas are often larger
than in glaucoma, usually measuring 15 mm or more in diameter. In spite of this great size, they are clear, and there is no evidence
of haziness or tears in Descemet’s
mem-brane. Corneas of this size in congenital glaucoma would usually not be clear. The condition is bilateral, more or less equal in
degree, inherited as a sex-linked trait and almost always found in males.
Corneal Opacification: Any condition
which causes corneal opacity in infants can be confused with congenital glaucoma. In
this group are included (a) intrauterine or infantile inflammations of the cornea such
as interstitial keratitis, viral infiammations such as smallpox or chickenpox and
intra-uterine gonorrhea, (b) Hurler’s syndrome
(
gargoylism), (c) blue sclerotic syndrome,(d) congenital idiopathic edema of the
cor-nea, and (e) congenital corneal dystrophy.
Secondary Glaucoma: Glaucoma may be
associated with developmental ocular anom-alies such as aninidia and microcornea. Glaucoma in the infant may he secondary
to ocular trauma and disease, e.g., corneal perforation with iris incarceration, retino-blastoma, and retrolental fibroplasia. Glau-coma may be associated with such systemic
disorders as neurofibromatosis, nevus flam-meus with glaucoma (Sturge-Weber syn-drome, if the brain is involved; choroidal
angiomatosis is often present also),3 and Lowe’s syndrome (glaucoma associated with cataract, mental deficiency, muscular
dys-trophy, and renal disease).4 In many of
these conditions goniotomy is either not
Some success has been achieved with mul-tiple operations for the glaucoma associated with nevus flammeus.
PROGNOSIS
With revival and refinement of the
goni-otomy operation by Otto Barkan,5 the
prog-nosis in congenital glaucoma has become
good. It is now possible to cure more than
80%, although not necessarily with one operation. “Cure” means permanent
nor-malization of the pressure and the preven-tion of any further damage during the rest of the patient’s life. The prognosis is in-fluenced by age of onset and corneal
diam-eter. If the onset is very early, i.e., at birth or soon after, the prognosis is
defi-nitely worse. It has also been noted that if
the diagnosis is made within 2 months of birth more reoperations are necessary than when the glaucoma is noted at a later date
(
obviously the more severe conditions arediagnosed earlier). Corneal diameter is an index of duration and severity. If the cor-neal diameter is less than 13 mm the
prog-nosis is good, diameter from 13 to 14 mm indicates a fair prognosis, and a diameter
greater than 14 mm indicates a poor prog-nosis.
TREATMENT
As indicated, the treatment of congenital
glaucoma is surgical. It is generally felt that the operation of choice is goniotomy. This
is best done with direct visualization of the chamber angle through a contact lens (Fig.
2). A
needlelike knife with a tapering shaftis thrust through the peripheral cornea just within the limbus. It is passed across the
anterior chamber and the tip inserted into
the trabecular zone anterior to the insertion of the iris root. An incision is made at this point along approximately one-third of the circumference of the angle. The knife is withdrawn and the anterior chamber
re-formed with air if necessary. There are few hazards to the eye, and no more hazard to the general health of the infant than would
he associated with any general anesthetic.
It is usually necessary to hospitalize the infant for only one or two days. Both eyes
can be operated upon at the same time. The operation can be repeated and does not cause major structural damage which
would preclude other types of surgery being
performed later.
Miotics are usually used in the immedi-ate postoperative period to keep the iris pulled away from the incision.
Reexamina-tion under general anesthesia is performed approximately 6 weeks after surgery.
ETIOLOGY
The etiology of congenital glaucoma and the reason for success of the goniotomy
op-eration are not clearly understood. It is known that there is diminished “facility of outflow” (a measurement by tonography of
how readily aqueous passes out through the filtration angle of the anterior chamber) indicating increased resistance to the nor-mal escape of aqueous from the eye. It is
also known that after a successful goniot-omy operation, the facility of outflow be-comes normal. It has been theorized that
muscle fibers from the ciliary body insert too far anteriorly.6 There are many other theories, but these are not within the scope of this paper. Those interested may consult
articles by Shaffer7 and Bettman.8
SUMMARY
Certain important points concerning
con-genital glaucoma should be remembered. The pediatrician should be suspicious of irritation of the eyes in an infant. Photo-phobia, lacrimation, and/or haziness of the
cornea should make one suspect congenital glaucoma and call for competent ophthal-mological examination. These findings mdi-cate congenital glaucoma until proven otherwise. Medical therapy should not be
attempted except as a supplement to
REFERENCES
1. Scheie, H. G. : Surgery in congenital glaucoma. Amer. J. Ophth., 45:936, 1958.
2 Shaffer, R. N. : Goniotomy technique in
con-genital glaucoma. Amer. J. Ophth., 47:90,
1959.
3. Jones, I. S., and Cleasby, G. W. : Hemangioma of the choroid: clinicopathologic analysis. Amer. J. Ophth., 48:612, 1959.
4. Falls, H. F.: Ocular manifestations of chronic
renal tubular insufficiency syndromes. Arch. Ophth., 62: 188, 1959.
5. Barkan, 0. : Technic of goniotomy. Arch.
Ophth., 19:217, 1938.
6. Maumenee, A. E. : The pathogenesis of con-genital glaucoma. Amer. J. Ophth., 47:827,
1959.
7. Shaffer, R. N. : Pathogenesis of congenital
glaucoma : gonioscopic and microscopic
anat-omy. Trans. Amer. Acad. Ophth. Otol., 59: 297, 1955.
8. Betian, J. W.: Goniotomy: clinical value.
